本文旨在探讨现浇磷石膏墙体对钢筋混凝土框架结构抗震性能的影响,通过对单榀填充墙钢筋混凝土框架结构在低周往复荷载作用下应力应变的数值分析,对比研究磷石膏墙体与砌体填充墙墙体材料、孔洞效应、高宽比等参数对钢筋混凝土框架抗震性能影响.结果表明:磷石膏墙框架结构相较砌体墙框架结构具有更高的承载力及更突出的延性性能、耗能能力;门洞开洞位置对结构承载力、初始刚度影响较小,基本可以忽略;相同条件下墙体高宽比越大,结构屈服荷载、抗侧刚度越小;结构承载力和初始刚度随高宽比的增大而降低,但在较低的高宽比范围内影响较小.本文可为磷石膏填充墙钢筋混凝土框架结构设计提供参考依据.

在武汉地区市政项目建设中的深基坑开挖往往面临周边建筑紧邻、地下管线复杂、软土覆盖深厚等问题,深基坑变形控制要求高.对于软土地区的超深基坑,基坑内被动区土体加固作为一种超前支护方式对深基坑的变形控制效果十分显著.以武汉市黄孝河、机场河水环境综合治理二期工程中的常青公园地下调蓄池工程软土深基坑为例,结合武汉和上海地区的工程经验及相关规程,通过现场和室内土工试验获得基坑各土层的物理力学参数,结合PLAXIS 3D岩土有限元分析软件建立了基坑三维数值模型,对基坑围护桩体水平位移和内支撑轴力进行了数值模拟,并将数值模拟结果与监测结果进行了对比,并对基坑加固体的尺寸参数和物理力学参数对基坑变形的影响进行了模拟分析.结果表明:基坑围护桩体水平位移和内支撑轴力的数值模拟结果与监测结果的变化规律基本一致,验证了数值模型模拟的精确性和合理性;对于矩形截面的加固体,加固体宽度的有效值范围为0.5H～1.0H,超过该有效值范围后基坑中间软土易出现"拱起效应";加固体深度的有效值范围为0.8H～1.3H,超过该有效值范围后对基坑变形控制的影响不明显;基坑加固体内摩擦角和压缩模量的增大可以有效控制基坑的变形,基坑加固体黏聚力的变化对基坑变形的控制效果不明显.该研究结果对类似基坑工程加固体设计具有参考价值.

Taking the rail transit tunnel in southwestern China as an example, the surrounding rock stability of mining excavation tunnel is analyzed by the method of three-dimensional finite element numerical simulation.Combined with the actual construction process, simulating tunnel structure stability characteristics of the whole section method with retaining substructure and without retaining substructure as well as two-bench excavation method, the variation law of parameters, such as displacement and stress and plastic deformation of surrounding rock, supporting structure internal force, are comprehensively evaluated.In the final, the optimal design of excavation and support processes in the tunnel project is proposed.

基于顶管接头接触面压应力为线性分布的假定,以管道截面受压区间比和内外径比为基础变量,推导了顶力合力、力矩和偏心距的解析公式.由顶管接头的变形约束条件,推导了受压区间比基于管道偏转角、管线转弯半径的解析公式.在此基础上就可以基于受压区间比、顶力合力偏心距、管道偏转角、管线转弯半径这四个变量之一计算允许最大顸力,或由已知施工顶力计算允许最大偏心距、允许最大偏转角或允许最小转弯半径.为方便应用,根据解析公式编制有关系数的图表供查询使用.最后推导了压应力为二次方分布条件下的解析公式,并进行了初步的对比研究.

本文以送水泵房为分析对象,采用分部计算法、等效框架法、有限元整体计算法对比分析,通过计算分析比较发现在外侧水土压力工况下,上部框架的约束使下部壁板外侧竖向弯矩明显减少,其减小幅度受壁板与框架柱的线刚度比值的控制,并据此得出等效框架计算法中等效宽度的取值方法,以及分部计算法的适用条件.

某输水隧洞位于过江段的淤泥质软土中,采用外衬管片—内衬砼—输水钢管三层复合结构,为了解其受力特性,利用ANASYS有限元软件进行数值建模计算分析.对比了3种不同填充砼高度的复合结构形式在管片拼装、混凝土浇筑和钢管安装及通水运营等阶段的受力情况.研究结果表明,3种结构在施工阶段的受力情况相近,受到填充砼及输水钢管自重影响而略有差别.进入运营期后,内水压是不同结构管片、填充砼、钢管受力形成差异的原因,作用在钢管上的内水压能够通过填充砼传递到管片上,传递效果的强弱、范围及应力集中现象决定了复合结构各部分的最终受力情况,研究成果可供类似工程参考.

将预应力超高性能混凝土屋面梁应用于实际工程,对预应力超高性能混凝土梁采用欧洲规范和湖南大学编制的省标(报批稿)进行有限元分析和计算,并现场采用1∶1的足尺模型试验以检验预应力超高性能混凝土梁的受力性能.对试验结果与理论计算结果进行对比分析,为工程应用提供参考.

This paper mainly discussed the technical characteristics of small diameter shield in municipal pipeline engineering.Combined with a project example,it investigated the choice of shield equipment,the design of shield shaft,segment design,the construction measures in special strata,and the selection of anti-corrosion and waterproofing.The successful completion of this project proved that small diameter shields deserve to be popularized in municipal pipelines.

对取水泵房采用桩基支护进行深基坑开挖的设计、施工进行了比较深入的分析,通过对圆形基坑咬合式桩基支护进行受力力学分析,认为圆形深基坑桩基支护按圆柱壳的力学模型计算过于理想化.本文通过增设环形水平支撑将支护桩基转换成多跨连续梁模型进行计算,并应用于工程实际,同时提出了设计与施工过程中应注意的要点.

How to easily determine the optimal slab thickness according to its internal forces is often encountered in the structural design of the water supply and drainage.As for the flexural reinforced concrete slabs,this paper intends to use analytical formula,discrete numerical calculation and fitting function to derive a formula for optimal slab thickness that is available for the practical application,and then checks its feasibility in real engineering projects.

Taking the water intake pumping houses of four large water treatment plants in Chongqing City for example,the experience in design and construction of deep well pumping houses and large-span factory buildings in water intake projects in mountain areas was summarized,and some key points that should be noted in their design and construction were proposed to provide references for similar projects.

<正>江北城CBD区域位于长江与嘉陵江交汇处,是重庆市在建的中央商务区。为营造一个节约能源、节约资源、环境友好的城市区域,在CBD区域进行江水源热泵集中供冷、供热项目建设,为区域内的公共建筑空调系统提供冷热源。本工程是江水源热泵项目2号能源站的取水工程,工程总规模为一万吨/小时。由于航道部门要求取水头部只能设置在千厮门大桥50m范围内,而且为避开能源站一期取水的渗渠,取水管如上图弯折布置。其中低位取水口至泵房的自流管长约436m,高位取水口至总管的长约73m。泵房平面总尺寸为75.83×33.2m,包括取水泵房、沉砂

It is sometimes encountered that a large cross-section beam are vertically connected to the wall in the structural design of the water supply and waste water engineering.For this type of structures,after statistical analysis of finite element analysis results,it is concluded that equivalent-framework calculation method can be used if the height of beam is not more than the half height of wall,and equivalent width of wall is only related to four factors,that is the height of wall,the thickness of wall,the height of beam and the width of beam.For easy to use,the table of equivalent width is provided.Suggestions for the calculation methods and the construction of the connections between the beam end and the wall were offered in this paper.

The thought of the design and the experimental data of construction of pipe jacking in a variety of lithologic strata and mixed grounds by summarizing the pipe jacking engineering practices in Chongqing region was presented in this paper.It is expected to provide references for the pipe jacking design and construction under similar engineering geological conditions.

One ashore pump house of a project has been laid under water for an average years.Its structure is a closed reinforced concrete shell containment structure.Its outer shell is supported by frame structure inside,and the auxiliary anti-flotation benefits are provided by the pile foundation at its base.The arrangement of anti-flotation piles is analyzed in this paper.Finally,according to the test result of the static load tests on anti-pull bearing capacity of large diameter rock-socketed piles,suggestions about the value determination of ultimate shaft resistance in the anti-flotation design of rock-socketed piles are proposed.

取水泵房的结构设计应解决好三方面问题:周围介质对结构的压力与约束;抗浮措施;温度作用与裂缝控制;合理的结构形式与相应的内力分析方法.本文结合工程实例重点讨论结构形式与内力分析要点.